What does it mean when your lower spine X-ray report says spur?

Likely bony spur. Bony spurs develop as one gets older, from wear and tear on joints, etc. This can also happen in the spinal column. They are important to note since they can be near nerves, etc. And may have to be removed.
Getting older. Spur usually refers to osteophyte or degenerative change in spine. Spur is common finding of piece of bone projecting off vertebra body. It is usually seen anteriorly but can be sometimes noted laterally and posteriorly.